Dumbbells are commonly used for exercising the body, particularly the arms, and comprise a grip portion of relatively smaller diameter and a pair of bells of larger diameter, one at each end of the grip portion.
The dumbbells are commonly made of an integral piece of cast metal. Such dumbbells, being hard and unyielding, are more likely to mar or damage floors or furnishings which they happen to strike, are noisy when struck together or against other objects, can cause serious injury if they strike the body of a person, and often are abrasive or uncomfortable to handle or carry. It is known, as disclosed in U.S. Pat. No. 3,482,834 of James, Jr., issued Dec. 9, 1969, to make a dumbbell of a hard material, such as cement, covered with a yieldable plastic having wear-resistant qualities. While such a dumbbell provides some protection against marring and against unnecessary noise and injury to persons, and provides an improved "feel", the interior weighting material (e.g. cement) is dense and hard, and hence imparts to the assembly a substantial unyielding character when dropped, for example.
U.S. Pat. No. 3,334,899 of J. M. Bosko et al, issued Aug. 8, 1967, shows an integral hollow self-supporting dumbbell casing filled with fluid (FIG. 5), and also shows a dumbbell in which hollow fluid-containing end spheres of rubber or the like are screw-fitted to an intervening handle so that either the handle length or the bell can be changed. In the first form of this device mentioned above, it is clear that the hard rubber is sufficiently strong, dense and inflexible to maintain structural integrity of the dumbbell even though it is filled with weighting material, and hence it cannot be yielding in nature; the principal purpose of the device is to enable filling of the dumbbell to different levels, thereby to vary its total weight for different exercise purposes. The same may be said of the embodiment of the Bosko et al FIG. 6, in which the rubber bells are of such strength and rigidity as to enable them, for example, to be screwed on to the mating threads of a connecting rod. Accordingly, this dumbbell is also not as soft, pliable or yieldable as would be desired.
The present invention provides a new and useful form of dumbbell which is exceptionally soft and pleasing to the touch, is highly yielding so as not to mar furnishings and the like, is simple to make, and yet maintains its configurational integrity, thereby overcoming one or more of the above-mentioned drawbacks of previously-known dumbbells.